Water → 5-Methoxynaphthalen-2-amine

HRID 453264Notes

Reaction equation

HRID 453264 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][C:8]=2[OH:12])[CH:3]=1.[H-].[Na+].[CH3:15]I.O>CN(C)C=O>[NH2:1][C:2]1[CH:11]=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][C:8]=2[O:12][CH3:15])[CH:3]=1

Participants

6

Reactant 4

HCID 962WaterHCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 902956-Aminonaphthol

Product 1

HCID 129927625-Methoxynaphthalen-2-amineYield 77.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
5 °C

Procedure

A solution of commercially available 2-amino-5-hydroxynaphthalene (5.16 g, 31.48 mmol) in dimethylformamide (125 ml) was cooled with ice in an inert nitrogen atmosphere. Subsequently, NaH (1.39 g dispersion in a mineral oil at 60%, 34.6 mmoles) was added keeping the temperature below 10° C. and was shaken during 15 min. at ≈5° C. Subsequently methyl iodide (4.47 g, 31.48 mmol) solved in dimethylformamide (5 ml) was added and was left stirring at room temperature during 20 hrs. Water was added and it was evaporated to dryness in a rotavapor. To the remaining residue, water and ethylic ether were added. The aqueous phase was newly extracted with ether and the collection of organic phases was dried over Na2SO4, filtered, and evaporated to dryness. To the resulting crude slurry, a mixture of isopropylic alcohol/petroleum ether 1/1 was added, stirred during a few minutes and the insoluble precipitate was filtered. 4.21 g (77%) of 2-amino-5-methoxynaphthalene were obtained, with a purity determined by HPLC of 99%.

Workup

  1. customthe temperature below 10° C.
  2. additionwas added
  3. waitwas left
  4. stirringstirring at room temperature during 20 hrs
  5. customit was evaporated to dryness in a rotavapor
  6. additionTo the remaining residue, water and ethylic ether were added
  7. extractionThe aqueous phase was newly extracted with ether
  8. customthe collection of organic phases
  9. dry with materialwas dried over Na2SO4
  10. filtrationfiltered
  11. customevaporated to dryness
  12. additionTo the resulting crude slurry, a mixture of isopropylic alcohol/petroleum ether 1/1
  13. additionwas added
  14. stirringstirred during a few minutes
  15. filtrationthe insoluble precipitate was filtered

Sources & evidence

ORD record
ord-2dfa08e54ded4636b70d5fabbae55d6a
Source dataset
uspto-grants-2013_07
Patent number
US08492425B2

Reaction notes

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